The invention relates to a process for the preparation of linear or branched sulfur-containing polymers such as polyarylene sulfides, in particular polyphenylene sulfide (PPS).
U.S. Pat. No. 4,910,294 describes a process for the preparation of PPS. The monomers used are dihalogenated, aromatic hydrocarbons, in particular dichlorobenzene (DCB), and sodium sulfide, which are reacted in a highboiling, dipolar aprotic solvent such as N-methylpyrrolidone (NMP). The sodium chloride which forms as a byproduct is removed from the polymer after the polymerization reaction has finished either, as described in EP 220 490, by filtering the reaction solution whilst it is still hot at elevated temperature under pressure, or by dissolving in water. According to the prior art, the molar mass of the end product of the polycondensation reaction is attained before the sodium chloride is removed.
A disadvantage of this preparation process is, however, that the space-time yield of the reactors is unsatisfactory because a relatively long reaction time is required.
The object is therefore to overcome this disadvantage.